Scraping becomes unethical when it turns into a DOS, doesn't it? In some cases it wouldn't be an issue, but some scraping definitely makes the service less responsive.
Yep, this is the only thing which I agree with. When I scrape I always try to use as little resources as possible and make sure it’s appropriate for the size of the site I’m scraping (I wouldn’t care about sending 1k requests/second to Facebook, but wouldn’t send more than a dozen few per second to a little e-commerce store).